This invention relates to an orthodontic appliance, and more particularly to an orthodontic appliance for expanding or otherwise moving any desired tooth or teeth of the upper arch, including substantially the entire upper arch.
Generally, orthodontics is a field of dentistry in which the position of the teeth are physically moved relative to one another and relative to the maxilla and mandible, such that after treatment the teeth are in proper relation to one another and to the facial skeletal structure of the patient. Treatment begins by the treating dentist carefully examining the patient's mouth, both visually and radiographically, so as to determine the existing positions of the teeth and the structure of the maxilla and the mandible. The dentist then plans a course of treatment to selectively move certain of the teeth so that after a period of active orthodontic treatment, the teeth will be disposed in a proper positional relationship relative to one another and relative to the patient's facial skeletal structure. The treating dentist has a variety of appliances available for tipping the teeth, rotating them about a longitudinal axis of the tooth, or moving the teeth in posterior, anterior, buccal, or lingual direction. In additional, teeth may be expanded, contracted, intruded, torqued, or de-rotated, as decided by the treating dentist. Generally, existing appliances are available for carrying out each one of these functions on selected teeth of the patient.
Oftentimes, during treatment, it is necessary to expand (or contract) one or more teeth on the patient's arch. Such expansion of the arch is now carried out utilizing appliances referred to as transpalatal expansion appliances.
In addition, it is known that a so-called Crozat appliance may be utilized which has a generally rectangular-shaped crib adapted to be removably fitted over a selected pair of opposed molars on the upper arch. This Crozat appliance has short extensions on it which could be resiliently bent so as to contact an adjacent tooth and to apply a transverse corrective force to the tooth. However, since the Crozat appliance was removable, it did not have a precise fit on the teeth on which it was located, and thus could not repeatedly apply the desired corrective forces. Additionally, the corrective force applied by the Crozat appliance was transmitted to the teeth on which the removable Crozat appliance was attached, thus inducing reactive forces to these teeth, which would cause the teeth on which the appliance is mounted also to move. Since the Crozat appliance is removable, it was impossible to simultaneously utilize fixed bonded or bracketed orthodontic appliances with the Crozat appliance.
Palatal arch bars, such as shown in U.S. Pat. Nos. 3,792,529 and 4,592,725, invented by Robert A. Goshgarian are known in which a band is applied to a selected pair of opposed teeth of the upper arch, typically the patient's maxillary first permanent molars, for de-rotating, expanding, contracting, intruding, and/or torquing only the first permanent molars to a desired position.